This project will assess the impact of recent Medicare policy changes on racial/ethnic disparities in mental health (MH) care. Medicare is the most common source of coverage for elderly and non-elderly disabled Americans with mental illness. Two recent policy changes have the potential to reduce wide disparities in access to mental health care, including care provided by primary care providers (PCPs) and specialty mental health providers (MHPs). Specifically, the Affordable Care Act (ACA) temporarily increased payments in 2013- 2014 by up to 25 percent for PCPs caring for Full Subsidy dual-eligible beneficiaries. Separately, the Medicare Improvements for Patients and Providers Act (MIPPA) gradually increased MHP payments (2009-2014) by up to 37 percent for Full Subsidy beneficiaries, and reduced beneficiary coinsurance for MHP visits from 50% to 20% for other beneficiaries (i.e., Partial Subsidy beneficiaries with incomes just above eligibility for Full Subsidies). In other settings, changes in provider payments and cost-sharing have been effective policy levers in modifying care utilization and access. In Medicare, these policies could reduce disparities by improving access to care for low-income income and Full Subsidy dual-eligibles, who are disproportionately racial/ethnic minorities; but there is little data on their effects. Despite the limited evidence, 34 states dropped PCP payment rates in 2015 (back to pre-2013 levels), while 16 states have continued the payment increase. We will use the natural experiments created by the ACA and MIPPA to assess the effects of these policy changes on racial/ethnic disparities in MH care within three sets of outcomes: Aim 1) medical care and quality process measures (e.g., outpatient visits to PCPs and MHPs for mental health diagnoses, antidepressant use in major depression); Aim 2) clinical events (e.g., emergency department visits and hospitalizations); and Aim 3) total and component medical spending. We will use comprehensive Medicare claims data (2006-2018) to compare longitudinal changes for Black, Hispanic, Asian, Native American and White beneficiaries affected vs. unaffected by the policies using a difference-in-difference approach with fixed effects (within-person) estimation. To estimate the effects of each policy, our identification strategy exploits the staggered implementation of each policy, differences across states in the magnitude of the payment changes based on baseline payment rates, and variations in exposure associated with eligibility for Full vs. Partial low-income subsidies. We will compare four resulting policy exposure groups: 1) beneficiaries affected by the PCP (2013- 2014) and MHP payment increases; 2) beneficiaries affected by the extended PCP (2013-2018) and MHP payment increases; 3) beneficiaries affected only by the MHP cost-sharing decrease; and 4) beneficiaries unaffected by either policy (concurrent controls). The findings from this study have the potential to inform decision-makers seeking to reduce the substantial disparities in MH care with actionable findings, especially as the federal government and states make ongoing decisions about payment policy and benefit design.